In response to the devastation reported by Ukrainian President Volodymir Zelenskyy following his visit to the city of Bucha, President Joe Biden called for a war crimes trial for Russian President Vladimir Putin. In doing so, President Biden reemphasized comments he made last month saying President Putin “is a war criminal.”

“This guy is brutal. And what’s happening in Bucha is outrageous,” Biden said Monday. “We have to gather the information, we have to continue to provide Ukraine with the weapons they need to continue the fight, and we have to get all the detail so this can be an actual… wartime trial.”

President Zelenskyy’s trip to Bucha was his first reported trip out of Kyiv since Russia’s invasion began. It followed a pullout of Russian troops from Bucha and other towns in the Kyiv area.

According to Ukraine’s prosecutor-general, the bodies of 410 civilians have been removed from Kyiv-area towns that were recently retaken from Russian forces. Associated Press journalists saw the bodies of at least 21 people in various spots just around Bucha, some of whom had seemingly been killed deliberately at close range.

“It’s war crimes that will be recognized as genocide by the world,” Zelesnskyy said Monday. “We know about thousands of killed and tortured people with cut limbs, about raped women and killed children.”

While Biden did call for a war crimes trial Monday, he stopped short of describing the scenes in Bucha as genocide. Other world leaders responded with calls for tougher sanctions against the Kremlin, namely a cutoff of fuel imports from Russia. Germany reacted by expelling 40 Russian diplomats, and Lithuania threw out its Russian ambassador.

Russia’s pullout of Kyiv-area towns like Bucha comes amid a reorganization of Russian troops to focus on the disputed Donbas region. Michael Clarke, a British Security and Defense Analyst, said this indicates “the Russians have been beaten clearly in Kyiv” and “they’ve given up on on trying to take Kyiv for the time being.”

“I think that the Russians will find that they’ve got a pretty tough fight in the Donbas because they’ll be up against the best of the Ukrainian forces who are all concentrated and as they have been for the last eight years in that southeastern part of the country,” Clarke said Monday.